US1547111A - Water purification - Google Patents

Description

,l' atented July 2!, i925.

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amen 1w. rum, 'or wasmeron, msrnacr oroonunnm, assrenon or mm ro .1mm L. Evans, or 'omoj a warns ruarrrca'rron.

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Be it known that I, ALFRED N. Fnm, a'

citizen of the United States, residing at- Washington, in the"District of have invented a certain new and-nee ff Improvement in Water Purification,

which the following is a.- full, clear, and exact description. fyThis invention relates to this;1 art of'- uri or softemng. "water 'su as no. Willis for industria;l the; "in boilers laundries, textile and pe r industries, in

other industries where s ts other than salts of the alkali metals'are objectionable and it consists in-treating the waterhefore it is to be to remove the objectionable ma An object of this invention is to so treat the water that practimlly all theisalts in solution objectionable gualities are removed before the water is use Y {Another object .of 'this invention is to treat the; water with such chemicals that substantially all the objectionable ingredients are removed and yet the water can-.

not be over-treated, that is cannot take 11 any substantial --a. mount of the chemica with which it is treated.

4 further 0 ject of the invention is. to provide a simp e and method oi treatmg natural vzgtersnwtlii is relatively inexpensive in 1 opera. on.

Another phuric acid ofsnbstantiall' .all the sulphate salts whether they be sal alkaline earth or alkali metals..

according t m m; ess one may roceed with the two steps of the reaction y carry taneously or in op onal succewion, dependof the upon theconditions and un er which the process is being. o rated,. as will appear more fully herema r, but I will first describe these steps of the procees individually.

application ille'd 'ianuary 18, 1928. Be rial No. 815,768.

'c' of the ihve'ntion possible'toremove substan y-all the ing them out s1mul- To remove the bicarbonates or tengforary hardness first, I treat the water by terin it through a filter containing an excess '0 magnesium oxide, hydroxide or its equiv alent, to react with the bicar on'ates, trans forming them into the respective carbonates. Or if it be desired, the ma its equivalent can be 'adde agitated and the recipitate removed.

. For each molec e transformed, one molecule of a magnesium carbonate is formed from the magnesia. or its uivalent according to' the following equa one:

The calcium' and magnesium "carbonates -formed -from their. respective bicarbonates andfrom the magnesia involved in this re action are relatively insoluble and there"- esium oxide or and the. water a fore form precipitates. If there be any sodium in it forms magnesiumcarbonate hydroxide] and haps some sodium cars bona-te because 1; e reactions may not to completion both of which being solub e are retained in solution. If there .be an b1- umi-" carbonates, such a's-those ofiron or num, they are also precipitated and moved during-this ste -of the process.

Intrea 7 thewater-to'remove. the Billesire to u'seflan alkalm'e..earth carbonate,

referably in excess, such.',-"for'exam le, as Barium carbonate which reacts with t e 's'ulcarbonate present in the water,

y innatural' wate'rI.

phates in solution to formbarium sulphate and therespective carbonates of, the metals;

previously existing as a' Spch sulphates usually are calcium, magnesium or sodium sulphates. In the case of the calcium and magnesium sulphates, the barium carbonate reacts to form barium sulphate and calcium and magnesium carbonates, all of which are relatively insoluble and-are cording tothe following equations e CaS0,-BaOO,=BaSO,-C&CO, NasO -BaOQiliasO -Naflo,

precipitated. These reactions take place 'ac-' In the case of sodium sulphate, the reaction forms barium ,sul ate which is relatively insoluble and sodium-carbonate which remains in solution.

The majority of waters to be treated contain only normal amounts of bicarbonates with variable amounts of sulphates and with these either treatment can be used first but preferably the barium carbonate. If, however, the water to be treated contains more carbon dioxide in solution than nor- 'p mal surface waters, it may be preferable to treat this water with the ma esium compound first. This is because t e excess car on dioxide in solution would tend to dissolve a relatively larger amount of barium carbonate, which even though small is usually undesirable and it would have to be removed later. Also, if the water to be treated to be a itated with the added in an atmosphere having chemical instead 0 filtered through a bed containing it and if the water is of such a nature that it is more desirable to treat with the barium carbonate in the second step, this second stepshouldb'e carried out no carbon dioxide because its presence wil c ause apartial solution of the barium carbonate and this is objectionable for some purposes.

If the water to be treated contains large amounts of Sn] hates in solution, it is preferable to treat it with the barium carbonate first in order to precipitate a larger quantity of salts first, also because it has been found that the sulphates are more readily precipitated while bicarbonates are sti present. In order to get the best results the magnesium oxide should be prepared with special reference to the fineness and temperature of burning, as is well understood, so that it will be active chemically when added for treatment. The barium carbonate used in connection with the reaction with the sulphates is a product now obtainable .in .commercial quantities on the market. I

The small amounts of sodium carbonate and hydroxide which remain insolution as.

. a. r'esult of the reactions, render the solution slightly alkaline and this is not only not in urious for most-purposes, but is actually beneficial to boilers, valves, pipes, etc., of the system where it is used.

It may be noted that the chemicals added for treatment may; be added to the water and the water agitated to ensure complete reactions, or the water may be run throu h suitable filters containing thechemicals or treatment. In the former case the recipitated material may be removed by tration or sedimentation and in the lauer case the precipitates will be removed as formed. In either case the sus nded matter i'n'the water comes down with the precipitate and is removed at the same time.

It will also be noticed that in treating water according to my rocess that one does not need to be carefu about the amount of magnesium or barium salts added except to transform them into a that there must be a sufiicientf minimum amount to properl react with the salts in solution. This is because aniexccss of the added materials can not increase the soluble mineral contents of the water but they are substantially reduced after treating with my rocess.

Attention is also'directcd to the fact that in removing the bicarbonates and sulphates substantially all the scale forming compounds are removed, .so that my process may be operated to advantage in treating waters for use in boilers, as well as". for ma ny other industrial applications and uses.

It will be seen, also, that my roc'ess resents a simple, cheap and ellicient' met iod of treating in "large quantities s. large variety of natural waters. These waters may be treated at their source, or where they are wanted lor use, without a large investment in a hint and yet the treated water will be rec from all objectionable mineral contents.

It may also be noted that for waters in which'a relatively small quantity of the bicarbonates and sulphates occur that the treating agents employed may be used to react simultaneously-with the salts occurring in the water and the resulting precipitates removed.

F urtherinorc, it is to be understood that the particular com unds disclosed, and the procedure set fort 1;, are presented for pur-- poses of explanation'and illustration and that "arious e uivalents can be used and modifications oi said procedure can be made. without departing from my invention as defined in the appended claims.

Having described my invention, claim is: i a

1. The process of softening water which consists in treating it with an alkaline earth oxide, capable of decomposing bicarbonates and with a carbonate capable of preci 'itating sulphates and ,reactin with alkali salts ali carbonates.

purifying water which consists in treating the water with a carbonate capable of reactin with the sulphates what I '2. The process of to form relatively inso ubleprecipitates ad with an oxide capable pfreactmg with b1.-

carbonates and removing the precipitates from the solution. r

3. The process of purifying water which consists in treatingit-with a compound-capable of media with bicarbonates and with a corbonate caps 1e of reactin with alkaline earth sulphates-to form relatively insoluble sulphates and carbonates, and removing the insoluble compounds from the solution.

4. The recess of purifying water for boilers which consists in treating it with a cofipound capable of reactin with alkaline ea bicarbonates to-form re atively insoluble carbonates, and with a carbonate capable of reacting with alkaline'earth sulphates to form relatively insoluble sulphates, and reacting with alkali sulphates to precipitate insoluble sulphates and form alkali carbonates, thereb precipitating substantially all objectionab e mineral compounds.

5. The process of softening water which consists in treating it with an oxide capable of reacting with bicarbonates, other than alkali bicarbonates, to form relatively in-. soluble carbonates and treating with an alkaline earth carbonate capable of reacting with sulphates in' the water, other than alkali sulphates, forming relatively insoluble carbonates and insoluble sulphates and removing such precipitates from the water.

6. The process of purifying water which consists in treating it with an alkaline earth carbonate to react with alkaline earth sulphates to form relatively insoluble sulphates and with an alkaline earth oxide capable of reacting with alkaline earth bicarbonates to form relatively insoluble carbonates and removing such relatively insoluble compounds.

7. The process of purifying water for boilers and the like which consists in treat ing it with magnesium oxide and an alkaline earth carbonateto react with the bicarbonates and sul hates in solution, forming relatively insolu ble alkaline earth carbonates and sulphates, said magnesium oxide and alkaline earth carbonate also reacting with alkali bicarbonates and sulphates to form alkali carbonates and hydroxides.

8. The process of softening water which consists in treating it with magnesium oxide and barium carbonate, the ma nesLum oxide reactin with alkaline earth bicarbonates to form re atively insoluble alkaline earth carbonates in water, and reacting with'alkali bicarbonates' to form alkali carbonates and hydroxides, said barium carbonate reacting with alkaline earth sulphates to form barium sulphateand alkaline earth carbonates, and also reacting with alkalisulphates to form barium sulphate, and removing the relaprecipitates and suspended matter,

precipitates from the water.

-9. The process of purifying water which consists in treating it with an alkaline earth carbonate in excess to form relativel insoluble alkaline earth sulphates and 'al ali carbonates and treating it with magnesium oxide in excess to react with the bicarbonates to form relatively insoluble carbonates.

10. The process ofpurifying water which consists in treating it in optional succession with milk of magnesia in excess to react with the bicarbonates to form relatively insoluble carbonates and with barium carbonate inexcess to form relatively insoluble alkaline earth sulphates. r

11. The process of purifyingi water which consists in treating it with mil of magnesia and barium carbonate, both in excess, and removing the precipitates.

12. The process of purifying water which consists in removing the acid radical of all the sulphate salts in the water, decomposing the bicarbonates in the water and removing substantially all the carbonates by treating with barium carbonate and milkof magnesia and removing the precipitates formed.

13. The process of purifyin water which consists in 'rcmovin from tie water the salts of heavy metafii and the sulphates b treating the water with an oxide and Witl i an alkaline earth carbonate and removing the precipitates formed.

14. The process of urifyin water for boilers and the like which consists in treating it with magnesium oxide and barium tively insoluble carbonate to react with the bicarbonates and sulphates in solution, forming relatively insoluble alkaline earth carbonates and sulphates and filtering the water to remove the whereby substantially all the scale forming compounds are removed.

In testimony whereof, I hereunto aflix my signature.

ALFRED N. FINN.

of reacting with alkaline earth sulphates to form relativel insoluble sulphates, and reacting with alkali sul hates to precipitate insoluble sulphates an form alkali carbonates, thereb precipitating substantially all objectionab e mineral compounds.

5. The process of softening water which consists in treating it with an oxide capable of reacting with bicarbonates, other than alkali bicarbonates, to form relatively in-. soluble carbonates and treating with an alkaline earth carbonate capable of reacting with sulphates in' the water, other than alkali sulphates, forming relatively insoluble carbonates and insoluble sulphates and removing such precipitates from the water.

6. The process of purifying water which consists in treating it with an alkaline earth carbonate to react with alkaline earth sulphates to form relatively insoluble sulphates and with an alkaline earth oxide capable of reacting with alkaline earth bicarbonates to form relatively insoluble carbonates and removing such relatively insoluble compounds.

7. The process of purifying water for boilers and the like which consists in treating it with magnesium oxide and an alkaline earth carbonateto react with the bicarbonates and sulphates in solution, forming relatively insoluble alkaline earth carbonates and sulphates, said magnesium oxide and alkaline earth carbonate also reacting with alkali blCtlIbOIlfl-lJBS and sulphates to form alkali carbonates and hydroxides.

8. The process of softening water which consists in treating it with magnesium oxide and barium carbonate, the magnesium oxide reacting with alkaline earth bicarbonates to form relatively insoluble alkaline earth carbonates in water, and reacting with alkali bicarbonates to form alkali carbonates and hydroxides, said barium carbonate reacting with alkaline earth sulphates to form barium sulphate'and alkaline earth carbonates, and also reacting with alkali sulphates to form barium sulphate, and removing the relatively insoluble precipitates from the water.

9. The process of purifying water which consists in treating it with an alkaline earth carbonate in excess to form relativel insoluble alkaline earth sulphates and a1 ali carbonates and treating it with m esium oxide in excess to react with the bicarbonates to form ielatively insoluble carbonates.

10. The process of purifying water which consists in treating it in optional succession with milk of magnesia in excess to react with the bicarbonates to form relatively insoluble carbonates and with barium carbonate in excess to form relatively insoluble alkaline earth sulphates.

11. The process of purifyin water which consists in treating it with mil of magnesia and barium carbonate, both in excess, and removing the precipitates.

12. The process of purifying water which consists in removing the acid radical of all the sulphate salts in the water, decomposing the bicarbouates in the water and removing substantially all the carbonates by treating with barium carbonate and milkof ma nesi'a and removing the precipitates formed.

13. The process of purifyin water which consists in rciuovin from t e water the salts of heavy meta s and the sulphates b treating the water with an oxide and Wit an alkaline earth carbonate and removing the precipitates formed.

14. The process of urifyin water for boilers and the like which consists in treating it with magnesium oxide and barium carbonate to react with the bicarbonates and sulphates in solution, forming relatively insoluble alkaline earth carbonates and sulphates and filtering the water to remove the precipitates and suspended matter whereby substantially all the scale forming compounds are removed.

In testimony whereof, I hereunto aflix my signature.

ALFRED N. 'FINN.

V g Certificate of Correction. It is hereby certified that in Letters Patent No. 1,547,111. granted July 21.. 1925,

upon the application of Alfred Finn, a n improyement in Water Purification? tion requiring correction as follows Page the word in water and-line 41, after of W ashington District of Columbia, for

an error appears in the printed specifica- 3, line 40, claim 8, strike out the words bicai'bonates insert the words in the water; andthat the said Letters Patent should be read with this correction therein that the same may conform to the Signed and sealed this 22d day [snan] record of the case in the Patent Ofiice. of September, A, D. 1925.

y KARL FENNING,

Acting Commissioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,547,111. granted July 21. 1925, upon the application of Alfred Y. Finn, of hwhingtomlfistrict of Columbia, for an improvement in Water Purification; an error appears in the printed specification requiring correction as follows: Page 3, line 40. claim 8, strike out the words in Water and line 41, after the word hicarhonates insert the words in the water,- and that the said LettelePntent should be read with this correction therein that the same may conform to the record of the arse in the Patent Office.

Signed and sealed this 22d day of September, A, D. 1925.

[SEAL] KARL FENNING,

A cting Uommz'sez'onor of Patents.